Disregard the red circle and look at the white logo near the top. Now compare that to the white "logo" in this second picture, near where the bent over guy is reaching.
The above is a closeup from the image below.
What is the bent over guy's partner holding in his left hand?
I believe the backpack is from the other bomb site than your picture is showing. The other site was also where there was the pressure cooker remains. This bomb site was where the bomb was “in a metal container.” Look at this link and you will see a reflective (metalic?) container at the feet of a man. He is also carring a backpack. Could he have place this first bomb and then walked down the street and placed the backpack bomb in that location?
To find the refletive object follow the green line down the left half of the page until it cuts through the reflective object. That is about the location of where you say the bomb went off.
http://www.thegatewaypundit.com/wp-content/uploads/2013/04/pack-2.jpg
